A series of transition metal complexes of the general formula M(HL)2 (where H2L=2′-(4-dimethylaminobenzylidene)-2-hydroxybenzoylhydrazide, M=Ni, Cu, Zn, Cd) were prepared and characterized by elemental analysis, spectroscopic (IR, UV–vis) and the Ni(HL)2 was structurally characterized by X-ray crystallography. Single-crystal X-ray diffraction results suggest that Ni(II) central atom situated in a distorted square planar geometry is four-coordinated. The DNA-binding properties of these complexes with calf thymus DNA were also investigated by electronic absorption titration (UV spectroscopy) and fluorescence emission titration. The results showed that these complexes bind to DNA mainly via intercalative mode.

Aim To study the complex crystal structure of La(III) and N-(2-propionic acid)-salicyloyl hydrazone and to test bioactivity of the complex.Methods The crystal is obtained by solvent pervasion method,the structure is determined by single crystal X-ray diffraction analysis,bioactivity is tested by potted plant method.Results The complex is a novelty binuclear single crystal.The crystal complex crystallizes in the triclinic system with space group P-1,and parameters a=0.908 19(19) nm,b=1.233 2(3) nm,c=1.325 1 nm,α=104.157(4)°,β=99.312(4)°,γ=108.911(3)°,Z=2,R1=0.040 1,wR2=0.106 2,GOF=1.016.The complex can excellently inhibit Puccinia striiformis Westendrop and Pseudoperonospora cubensis and also can advance crop′s upgrowth.Conclusion The new complex crystal of La(Ⅲ) and N-(2-propionic acid)-salicyloyl hydrazone adds new contents for coordination chemistry and bioinorganic chemistry.The well bioactivity of the complex affords an applied foundation on the agriculture.

Complex 1 [Pr-2(H2L)(2)(HL)(2)(2,6-H(2)PDA)(H2O)(2)]center dot 2H(2)O and complex 2 [Eu-2(H2L)(2)(HL)(2)(2,6-H(2)PDA)(H2O)(2)]center dot 2H(2)O were obtained by reactions of N-(2-propionle acid)-salicyloyl hydrazone (C10H10N2O4, H3L), 2,6-pyridinedicarboxylic acid (2,6-H(2)PDA) and RE(NO3)(3)center dot nH(2)O (RE=Pr, Eu) at room temperature, and characterized by elemental analyses, IR, UV, and single crystal X-ray diffractometry. In addition, the DNA binding properties of the two complexes were Studied by means of UV absorption spectrum, emission spectroscopic spectrum, steady-state emission quenching and DNA competitive binding with ethidium bromide (EB). The results indicated that the two complexes bound to calf-thymus DNA in an intercalative mode.

A novel binuclear Cobalt(II) complex with N-(2-propionic acid)-salicyloyl hydrazone (C10H10N2O4, H3L) was prepared and characterized. The crystal structure of [Co(C10H9N2O4)2] · 3H2O was determined by X-ray single-crystal diffractometry. The Co2+ ion is six-coordinated by the carboxyl and acyl O atoms and azomethine N atoms of two tridentate N-(2-propionicacid)-salicyloyl hydrazone ligands, which form two stable five-numbered rings sharing one side in the keto form. The coordination environment around the Co2+ ion might be described as a distorted octahedron. Abundant hydrogen bonds of the types O-H…N and O-H…O between the water molecules and ligands not only form the three-dimensional network, but also provide an extrastability for the crystal. The complex was studied for the interaction with calf thymus DNA by electronic absorption titration and emission titration. The results show that the complex is bound to calf thymus DNA mainly by intercalation.

Complex 1 [Pr2(H2L)2(HL)2 (2,6-H2PDA)(H2O)2] · 2H2O and complex 2 [Eu2(H2L)2(HL)2(2,6- H2PDA) (H2O)2] · 2H2O were obtained by reactions of N-(2-propionic acid)-salicyloyl hydrazone (C10H10 N2O4, H3L), 2,6-pyridinedicarboxylic acid (2,6-H2PDA) and RE(NO3)3 · nH2O (RE=Pr, Eu) at room temperature, and characterized by elemental analyses, IR, UV, and single crystal X-ray diffractometry. In addition, the DNA binding properties of the two complexes were studied by means of UV absorption spectrum, emission spectroscopic spectrum, steady-state emission quenching and DNA competitive binding with ethidium bromide (EB). The results indicated that the two complexes bound to calf-thymus DNA in an intercalative mode.

A novel binuclear Smarium (III) complex with N-(2-propionic acid)-salicyloyl hydrazone (C10H10N2O4, H3L) was prepared and characterized. The crystal structure of [Sm2(H2L)2(HL)2(H2O)4] (1) was determined by X-ray single crystal diffractometry. 1 crystallizes in the monoclinic systerm, space group P2(1)/c, with a = 0.10229(2), c = 31.549(7), b = 0.70599(15) nm, and Z = 4. In the structure, Sm(III) is nine-coordinated by carboxyl O and acyl O atoms and imido N atoms of two ligands (H2L and HL forms) and O atoms from two water molecules. H2L and HL act as tridentate ligands which form two stable five-numbered chelating rings sharing one edge in the keto form for each ligand, and the carboxyl groups of two ligands were coordinated via bidentated bridging form. The coordination polyhedron around Sm (III) was described as a monocapped square antiprism. The inter- and intramolecular hydrogen bonds resulted in a three-dimensional network and provided extra stability for the structure. The complex was researched the interaction with calf thymus DNA by electronic absorption titration and emission titration. The results show that the complex is bound to calf thymus DNA mainly by intercalation .The complex also shows good fluorescence property.